V8 only firing on every second cylinder? Any Ideas

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hi-ling, Apr 6, 6:47am
Not saying your wrong, but just check your intake as the stock 2 barrel manifolds do not supply i bank for each barrel. They are a dual plane manifold and the runners actually overlay internally so that the engines intake pulses altenate from 1 barrel to the other to keep a constant airflow thru each barrel. So looking from the front of the motor, the left barrel feeds cyl's 1, 4, 6, 7 and the right barrel feeds, 2, 3, 5, 8.And going by your earlier post its missing on 8, 3, 5, 2 so I'd say right barrel of carb is playing up. Check out this reference and you'll see what im getting at.
http://victorylibrary.com/mopar/intake-tech-c.htm#dp
maturerx, Apr 6, 7:42am
If a points dizzy replace condenser, if not an original Lucas condense make sure it is tight in mount (Taiwanese condenser slightly smaller), otherwise you have a faulty Coil - Typical 3500 faults
bigfatmat1, Apr 6, 8:25am
Have you replaced the rotor in the dizzy! I did not see that in quick glance through the thread. it sounds like a breakdown in spark underload.
bigfatmat1, Apr 6, 8:28am
common problems I see with this kind of fault is no diagnossis so all possible parts are replaced but in the process something is not assembled and or set correctly and happens to be a new fault masking itself as a old fault. and old fault fixed So my advice replace rotor recheck all basics and timing voltage at coil ballast system if it has one. firing order points gap /dwell. then report back. Make sure correct coil is fitted as well.
quickstitch, Apr 6, 8:30am
have you got a good earth strap on the motor !
doug207, Apr 6, 8:42am
Are you running 12v or 6v to the coil!
mram, Apr 6, 8:56am
Im with all on the carburetor issue, very similar thing happened to my rover/p76 V8, with its 350 holley 2bbl was float level in the bowl and a blocked jet
clark20, Apr 6, 9:10am
Do you run an aircleaner! Something sucked into the carb and in the manifold!
babcorp, Apr 6, 9:22am
fuel pump. fuel filter.
sandndude, Apr 6, 9:23am
It's English. They put kidneys in pie's to.
NZTools, Apr 6, 9:36am
Eggzackerly
tmenz, Apr 6, 9:37am
Sounds like weak spark as it is OK with light load but no good under load.
Firing on second cylinders suggests that the coil is not able to build up charge quickly enough to fire on every one - points to faulty capacitor in the distributor or maybe the coil itself. Not uncommon for capacitors to be heat sensitive.
gadgit3, Apr 6, 9:38am
I'm liking this one too
easygoer, Apr 6, 10:03am
I'll go with the fuel theory also, problem with one barrel, soot indicates too much fuel, idles ok because the idle jet is fine but there is a problem with the main jet
frank_grimys, Apr 6, 10:08am
from the front of the motor the left side feeds cyl's 2,4,6,8, the right feeds 1,3,5,7.

12V coil, ballast not an issue for it, also brand new
les6, Apr 6, 10:10am
weak spark and too much gas fouling plugs!
snoopy221, Apr 6, 10:12am
Typical savage heat exchanger mounted in front of the dizzy!
If it ain't carb coil or condensor.
Then maybe ya got a water leak spraying ya dissy electrics!
mmmmmmmmmmm!
beast9, Apr 6, 10:45am
does it have the horrid lucas constant energy system that amplifies the signal from the dizzy to the coil if so check that and the pick up in the dizzy as they dont like moisture or heat had it in the old mongrel hang over 4x4
doug207, Apr 6, 11:35am
So you have an aftermarket manifold, not a machined standard item!
I'm with he above theory, had to go through my head on how my 3.5 manifold looked and I'd put $1 on it.
74nova, Apr 6, 11:39am
Sounds like hi-ling's on to something and makes sense. Pull the carbie off and look down the intake and follow the runners to see if the manifold is made that way.
goldilocks64, Apr 6, 8:01pm
good reading here . put a wide heat shield under the carb to stop the fuel boiling and all your problems will go :-)
skull, Apr 6, 9:01pm
So suddenly op needs a heat shield that he hasn't needed in the past! Highly unlikely I'd say.
nzemale, Apr 6, 9:26pm
Sounds like you have an air leak around the base of the carby - or an air leak around that area.
budgel, Apr 6, 9:58pm
An air leak would lean it out, not make it rich and soot up the plugs.
bigfatmat1, Apr 6, 10:41pm
incase you missed it replace the rotor! Dont just look and assume its ok.